what caused this?
- Thread starter blasty98
- Start date
i drained the oil, and the piece was sitting oin top of the crank so im lucky. it spins freely do im guesiing its all out. its a miracle it didnt score the head at all. it looks brand new. the piston probaly only had twenty hours on it? how could it wear that fast?
looks like you had good and bad luck! did you mic the piston and cylinder before assembly? if so what was the clearance? or did you just trust the piston manufacturer and assumed cylinder bore size? it can bite u in the rear sometimes. a loose assembly will typically run fine (not seize) until it slaps too much and breaks, its what that looks like.
Two words caused this...cast piston. Cast pistons are known to crack or shatter like yours did. Go with a wiseco there a forged piston and are alot stronger and lighter then cast.
Yep looks like it may have been slapping. I just had the same problem except mine shattered in about. 3 and a half billion pieces. Although i have too say it held up pretty well.. it had been in there for around 8 years lol
A damaged crank with crap tolerances typically will still "spin freely". If it's laying on top of the crank, it's typically not good, as the engine doesn't just stop on a dime. After the skirt falls into the crank case, and the engine BEGINS to die out, it still is spinning thousands of RPMs and the crank may or may not be getting chewed up by the skirt.
Blaner
Your Friendly South African Ambassador
i wouldnt take any chances with a smashed skirt, id split cases and clea,check and replace bearings if necessary
